Oil well tool



July 8, 1958 E. w. MCGAFFEY OIL. WELL TooL Filed Nov /l 1 g m I F m RM."{Vfwu P l Vwr. In. h f mM o w S 4 V .t 8 N e 3 l 8 2 I 2 l In M i oo 2rv m 2 .WJ x

July 8, 1958 OIL WELL TOOL 2 Sheets-Shee'. 2

Filed NOV. 15, 1952 v. E F .m n.6 ww mw o l( VR l. 2 o mm w i 3 3 5 Dlrmd5 a 3 Inn.' 4| ...3 a. a B. 3 a 4 lima? 2 2 i 9J 3 w 4 i 2 3 w 5 o 3l @u O f o n. M

United States Patent() 6 Claims. (Cl. 166-101) This invention relates tooil well tools and more particularly to an oil well cleaning device forwashing perforations in oil well casings.

In the production of oil wells, the bore hole is generally lined withcasing pipe extending downwardly in the well to oil sands at which pointthe pipe is perforated. The oil flows into the casingpipe through theseperforations, whence it is lifted to the surface. During this producingoperation the perforations oftentimes become. clogged with mud, sand,tar, or debrisof one sort or another, which tend to retard the flow ofoil intorthe casing pipe.

In the past, various types of well cleaning devices have beenfproposedfor removing such debris, one such form of device comprising spacedpacking means adapted' toy be lowered into the well adjacent theperforations to` be cleaned, and dening with the perforated casing pipea confined space into which uid mayv be pumped under pressure bysuitable cylinder; and piston arrangements in the tool, and forcedthrough the perforations. Another cleaning device of the above typeVuses spaced packing means, whose positions with respect to one anothermay be varied, whereby the conned space between the packers is varied,and thus the pressure changed to-force iiuid into or out of the adjacentperforations.

The present invention contemplates an improved oil v well cleaningdevice incorporating the above principles and has as its primary objectto provide greatly increasedr pressures in a confined packed-off spacefor forcing lluids through the perforations toY be cleaned.

Another object is to provide such a device in which suction pressuregreater than` has heretofore been attainable may be applied toperforations.

Still another object ofthe invention is to provide a device in which achemically treated fluid may be introduced into a confined spaceopposite the perforations, and forced through said perforationsundergreat pressure.

These and further objects and advantages of the invention are attainedby means of a cleaning toolprovided with spaced packing means, onepacking means being movable with respect tothe other. The tool alsoincludes ing uids through the perforations. In thisinstance thev pistonand cylinder arrangement provide an initial suction and then one packingmeans is moved away from theV other to increase the volumeofconlinedzfspace, therebyV causing an additional suction.

-A better understanding o they inventionand' itsy varif. l CC ousfeatures and advantages `will be had by referringl to the followingdetailed description in conjunction with the accompanying drawings, inwhich:

Figure 1 illustrates partly in section a preferred form of the wellcleaning device in one extreme` position;

Figure 2 illustrates the device of Fig. 1 in a second extreme position;v

Figure 3 illustrates a modification ofthe device ofrFig. l inoneposition; and Figure 4`shows the device of Fig. 3 in a second position.Referring to the drawing, there is shown in- Figures l and 2 a casingpipe 10 including a plurality of perforations or openings 11 throughwhich oil may be recovered fronrsurrounding oil. sands' in theearthforrnations.y The cleaning device of thepresent invention issupported on the end of the usuali drill pipe 12 or any other type ofsuitable tubingv providing a fluid passage. This connec-4 tion iseffected by means of a coupling 13havinga1owei annular shoulder 13. andincluding a one-way` check valve 14. Threadedly secured to the coupling`13 is an elongated hollow piston rod. 15y terminating in aV piston head16, the hollow tubular piston rod 15 being reciprocably'operable in amain cylinder -1-7; As shown, the upper end Wall 18 of the cylinder17includes a clutch mechanism 18 adapted'to engage a-r cooperating clutchmechanism in the piston head 16 when the piston rodv and piston head areat the upper end of their stroke; A breather port 17 is provided in theupper end of cylinder 17.

The cylinder 17 ispreferably divided into two chamf bers 21l and' 22 byacoupling 19 i`ncluding a second check valve 20, the two sections.defining these chambers being conveniently threaded to the coupling 19.

Within the-lower chamber 22 of the cylinderV 17 there is provided aplunger 23 mounted on' atubular member 24 reciprocably operable in thelower chamber 22 through bushing 2 5. The tubular memberr 24n extendsbeyond the llower endv of the cylinder 17 through a support 26 mountingstationary packing means 2,7. Plunger 23"and bushing 25 includerespectively clutch members23 yand 25 adapted to engage each othertoprevent relativero.- tation of the tubular member 24 and cylinder 17when the plunger and tubular member are in their lowermo'st posi-` tionfMounted exteriorly of thelower end of thev cylinder 17, on bushing 25,is a movable packing means 28. This packing means* 28 is rigidly securedto the, cylinder andbushing and thus will move with the cylinder as willbe described in connection with the operation of the tool. TheA support26 may take the' formv of a cylindricalsleeve surrounding and threadedlylocked tothe tubular, member24. This support includes at its lower endconically inwardly sloping surfaces 26 deiining slip expandf' ingAmeans. A lowery sleeve member 29 mounting, belly surface 26 of the slipexpander.,` A bayonet slot33 isv provided in the sleeve 294 and acooperating pin 34 on the; l

tubular member 24.

'Ilhe'extrerne lower end of the tube 24 includesports'risr having'fluidcommunication' up through thetube V24'y with.

a port 36 in the, upper end of tube 24am-da .port 36v in tlie'lower endof cylinder 17. This communication serves` tobypas's well fluids-aboutthe packing,meanswhenutheinstrument is moved in the bore hole. Theupperporimand 2s. j p Y Y Y ,f

lIn operation' of the device shown in' Figures l and 2,`

lowered into the well casing by the drill pipe 12 to a position oppositeperforations 11 to be cleaned. When the device is being lowered, thepiston 16 and clutch 16 arelin 'engagement with the end wall 18 andvclutch 18", and the plunger 23 and clutch 23 are in engagement 'with thebushing 25 andrnating clutch 25 as shown. fl his iirst`engagement ofclutch 16' and 18results from the weight of the cylinder 17,V whichweight is supported by the piston 16. YThe second engagement ofpclutch23 and 25` results from the weight of the tube 24, support 2,6, andthe'slip apparatus, which weight is supported by the top of bushing 25and lower portion of cylinder 17. xAs' soon as the tool is properlypositioned in the bore hole, the drill' pipe 12 is turned which rotatesthe hollow piston rod 15, cylinder 17, plunger 23, and hollow tubularmember 24 thereby rotating the pin 34 to move it along the horizontalportion of the bayonet slot 33. The sleeve 29, links 31,:and slips 32will not rotate `because of the friction of the belly springs 30 againstthe bore hole casing.V When ,the pin 34 has reached the end of thehorizontal portion of the bayonet slot 33 the drill tubing 12 is thenlowered and the pin enters the vertical leg of the 'bayonet slot.fFurther lowering of the drill pipe 12 causes the pin 34 and tube 24 totravel downwardly, and this action pushes the slips 32 along the slopingwalls 26 of ,thel slip expander, the slip including teeth which engagethe casing and throughly lock the lower portion of the tool in place.This action in turn insures that the packing means 2.7,is stationarilysecured with respect to the casing in the position as shown in Figure l.e IFluidis n ow pumped down through the drill pipe 12, hollow'piston rod15 and into the upper chamber 21 of the cylinder 17. This fluid willalso pass through the check valve 20 down into the lower` chamber 22 andthrough passage 37 in the tubular member 24 out into the coniined volumeV.

, Reciprocation of the drill pipe 12 will initially operate the piston16 to force uid in chamber 21 through the check valve 20 into chamber 22and down the passage 37 into the confined volume V as indicated bythearrows, increasing the pressure `between the spaced pacldng means 27 and28. As soon as the piston 16 reaches its lowermost position the shoulder13 of the coupling 13 will engage the outer end of wall 18 of thecylinder 17, therebyforcing the whole cylinder downwardly.

` Referring to Fig. 2, this action has the effect of moving the packingmeans 28 closer to the packing means 27 thereby decreasing the volume Vof the confined space. Furthermore, this action will decrease the volumeof the chamber 22 by virtue of the plunger 23 being secured to thetubular member 24 which is in turn locked by the spear slips 32 to thecasing. Thus the fluid in chamber 22 will be forced down the passage 37into the conned volume V further increasing the pressure of fluid inthis space. Fluid from chamber 22 cannot pass back up into chamber 21because of the one-way action of the check valve 20. With this greatlyincreased fluid pressure in the conned space V, the liquid therein willbe forced out through the perforations 11 with great force and thisfluid dow will serve to clean these perforations. Figure 2 illustratesthe relative positions of the piston 16, cylinder 17, and packing means27 and 28 at the end of the down stroke.

On the upstroke of the drill pipe 12, the piston 16 and hollow pistonrod move upwardly in the chamber 21 and during this action any duidabove the piston 16 is passed out into the surrounding casing throughthe port 17.- More liquid from a source disposed at the surface of thewell passes down through the pipe 12 and hollow piston rod 15 into thechamber 21 as the piston is raised.` When the piston 16 reaches the topof its stroke, it will engage the end wall 18 of the cylinder 17 andmove the cylinder 17 upwardly. This action has the effect of eX- pandingthe' conned volume V and the volume of the 4 lower chamber 22 whichexpansion will cause fluid from chamber 21 to enter chamber 22 as theplunger 23 approaches the bottom of the cylinder due to the upwardmovement of the cylinder. On the next down stroke of the drill pipe 12.the process is repeated and pressure is again built up in the confinedspace V.

Figures 3 and 4 show a modification of the tool of Figures 1 and 2useful for providing an extremely large suction to the perforations 11.This cleaning tool, however, may also be used as a simple pump. InFigures 3 and 4 the same reference numerals used in Figure l areemployed to designate corresponding elements and detailed description ofthese components is therefore not necessary. As shown, `the structurevis identical to the structure of Figures 1 and 2 except for thereversal of the two one-way valves 14 and 20 these valves beingdesignated 40 and 41 in Figures 3 and 4 and shown operable in theopposite direction.

In the operation of the device of VFigures 3 and 4, the tool is setopposite the perforations to be cleaned as in the case of the tool ofFigure 1. During the sucking operation, however, no fluid is introduceddown through the 'drill pipe 12, but rather the drill pipe is simplyreciprocated and serves as a conduit for conducting uid sucked olf thechamber 22 from the chamber 21. When piston inventionV will occur tothose 16 reaches the end of its downward stroke, as shown in Fig. 4, theshoulder 13 on the coupling 13 will engage the end of wall 18 of thecylinder 17 forcing the cylinder downwardly and causing the confinedvolume V to be decreased due to the movement of the movable packingmeans 28 towards the stationary packing means 27. This action forcesiluid in the confined space V up through the passage 37 in the tubularmember 24 into the chamber 22, past the check valve 41, into the chamber21, and thence through hollow piston rod 15 and drill pipe l2 to thesurface.

On the upstroke of the piston 16 and piston rod 15, a partial vacuumwill be created in the chamber 21 thereby sucking fluid fromchamber 22up past the check valve 41 and also sucking fluid from the confinedspace V up through passage 37y in the tubular member 24. When the piston16 engages the upper end of wall 18 of cylinder 17, the cylinder willthen be moved upward thereby increasing the volume of the confined spaceV and thus creating a further suction therein. Oil or other lluids whichlie behind the perforations in the formations will thus be suckedthrough the perforations 11, passed up through the passage 37, andsubsequently through the drill pipe 12 tothe surface.

It is to benoted that'in each of the described embodiments a two-foldaction takes place. First, a pressure or suction is built up by means ofthe piston 16 operating in the upper chamber of the cylinder 17.Secondly, a further pressure or suction is created by movement of themovable packing means 28 with respect to the stationary packing means27. A further pressure or suction associated with these two is built upin the chamber 22 by the action of plunger 24. `It is because of thiscompound effect of'building upvpressure or suctionY that a greatlyimproved cleaning operation is realizable with this too It is to benoted that by virtuek of the fact that the cylinder 17 in Fig. 1 is madein two sections connected by the coupling 19,1`check valve 20 may beeasily reversed. lSimilarly the coupling 13may `be removed, and thecheck valve 1'4 reversed. Thus the same tool may be used for a suckingor pumping operation.

Various modications within the spirit of the present sk illed in theart.

Iclaim: 31. In.' an apparatus'for cleaning perforations in oil wells,means for creating a uid pressure across said perforations Ibetween aconned space and the exterior of the casing, comprising in combination:a stationary packing means adapted to 'be secured -W-ithin and heldstationary 4with respect to said casing; a movable packing means spacedfrom said stationary packing means to dene, with said perforated casingand said stationary packing means, said confined space; a cylindersecured to and movable with said movable packing means; a plunger meansslid'ably receiving said cylinder and including a tubular member securedto said stationary packing means; a oneeway check valve ydividing lsaidcylinder into two chambers, said plunger means being operable in one ofsaid chambers; a piston means reciprocably receivable in lthe other ofsaid chambers and including means engaging said cylinder at ytheextremes of the stroke of said pis-ton means whereby yfurther movementof said piston means moves said cylinder; a one-way check valve in saidpiston means; fluid communicating means between said conned space andsaid one chamber; means for reciprocating ysaid piston means; and meansproviding a source o'f fluid communicating `with the said other chamberthrough said piston means.

2. The ysubject matter of `claim 1 wherein `said firstmentioned checkvalve comprises a Valve member which is seated by lilu-id pressure insaid one chamber and the other check valve comprises a valve memberlwhich is seated 'by iiuid pressure in the other chamber.

3. The subject matter of claim l ywherein said vfirstmentioned checkvalve comprises a valve member lwhich is unseated by fluid pressure insaid one chamber and the other check valve comprises a valve memberwhich is unseat/ed `by iluid pressure in the other chamber.

4. Apparatus for cleaning perforations in well casings, comprising incombination: movable and stationary packing means positionable withinand in sealing contact with a perforated Well casing at opposite sidesof perforations therein, -a cylinder extending axially of and vsecuredto the movable packing means, means for securing the stationary packingmeans in fixed position lwithin the casing, means movably connectingsaid stationary packing means and cylinder for movement ofthe latter andsaid movable packing means toward and limited movement away yfrom said'stationary packing means, plunger means axially movable in saidcylinder, means for limiting movement of the plunger means in thecylinder, said plunger means including a tubular member having meansIfor attachling the member to a tubing string for reciprocating Itheplunger means from the surface, movement of the tubular member in anaxial direction with -said stationary packing means held stationaryinitially moving said plunger means to one limit of its movement in thecylinder and thereafter moving the movable packing means toward thestationary packing means, movement of said tubular member in theopposite direction initially moving the plunger means to the other limitof its movement in the cylinder and thereafter moving t-he movablepacking means away from the stationary packing means, said cylinderhaving a transverse wall -dening with said plunger means a chamber whichis decreased in volume by movement of the plunger means toward said onelimit and increased in volume =by movement of the plunger means towardsaid other limit, said tubular member having first fluid passage meanscommunicating at one end to said chamber and open at the other end `forcommunication to the interior of a tubing string `secured thereto,-there vbeing second iiuid passage means communicating said chamber tothe space between said packing means, and one way check valve means insaid tirst passage means.

5. The subject matter of claim 2 wherein `said check valve meanscomprises a valve member which is seated by iiuid pressure in saidchamber.

6. The ysubject matter of claim 2 whereinsaid check valve meanscomprises `a valve member which is unseated by `fluid pressure in saidchamber.

References Cited in the file of this patent UNITED STATES PATENTS1,919,350 Wickersham July 25, 1933 2,052,006 Taylor Aug. 25, 19362,077,022 Spencer et al. Apr. 13, 1937 2,159,023 Hayward May 23, 19392,290,441 McGaey July 21, 1942

